Air seal for separating devices



Nov. 17, 1959 R. M. WILLIAMS AIR SEALv FOR SEPARATING DEVICES 2 Sheets-Sheet 1 Filed May 7, 1956 i a MM M m a No). 17, 1959 R. M. WILLIAMS 2,9 ,1

AIR SEAL FOR SEPARATING DEVICES Filed May 7, 1956 2 Sheets-Sheet 2' "includes a housing 12 of two principal chambers. The outer chamber 14 is used United States Patent 2,913,109 AIR SEAL FOR SEPARATING DEVICES Robert M. Williams, Kirkwood, Mo., assignor to Williams Patent Crusher and Pulverizer C0., Inc., St. Louis, Mo., a corporation of Missouri Application May 7, 1956, Serial No. 583,182

7 Claims. (Cl. 209-138) This invention relates to the sealing art in general and more particularly to air seals which are used to protect moving members from the harmful effects produced on them by foreign substances.

In the past, mechancial sealing devices have been constructed to shield and to sweep the area formed between relatively moving members in air separators. These known devices have themselves been the cause of harmful circulation of substances and have contributed to the erosive deterioration and inducement of high friction between the moving members.

It is therefore an object of the present invention to prolong the useful life of the relatively movable members in air separating devices and the like.

Another object of the present invention is to provide an air seal for use in air separating devices and the like which prevents harmful circulation and accumulation ofsubstances which ultimately cause wear and friction between the relatively movable members therein.

Another object of the present invention is to providean inexpensive yet effective air seal between relatively movable members in air separating devices and the like.

Yet another object of the present invention is to draw clean air from a dirt free area between the relatively movable members and cause it to flow into an air separating device to keep the members free from harmful deposits.

Other objects and advantages of the present invention will become apparent after considering the following detailed specification in connection with the accompanying drawings.

The invention consists in sealing the annular space between the feed tube and rotary sleeve of the blower in a simple way with dust free air so that Wear and friction or braking action can be reduced or elimiated. The sealing means broadly comprises utilizing a conduit open from atmosphere to the space between the feed tube and blower sleeve which is at a pressure less than atmosphere and in making the conduit large enough to supply an excess volume of air so that the internally generated dust cannot leak into the annular space mentioned.

In the drawings:

Fig. l is a vertical cross-sectional View taken along line 1--1 in Fig. 2 of an air separator that is provided with an air sealing device constructed according to the teachings of the present invention,

Fig. 2 is a cross-sectional viewtaken along line 2-2 in Fig. 1,

Fig. 3 is a fragmentary cross-sectional view taken along line 3-3 in Fig. 1,

Fig. 4 is a fragmentary line 4-4 in Fig. 1, and

Fig. 5 is a fragmentary view of the air separator of Fig. 1 showing a modification of the air sealing device.

Referring to the drawings more particularly by reference numerals, number refers generally to an air separating device constructed according to the teachings of the present invention. The air separating device 10, funnel section which encloses cross-sectional view taken along for accumulating the finer chamber 16. The disc 32 2 particles being separated; and the inner chamber 16 is for accumulating the heavier and coarser particles, The inner chamber 16 .has the same sectional contour as the outer wall of the housing The top surface of the housing 12 is enclosed by a circular cover 18 which is Welded or otherwise secured to the upper edge thereof. A feeder tube 20 extends downwardly and angularly throughthe central portion of the cover 18 and connects at its lower end with a vertical feeder tube 22. The,vertical tube 22 extends down into the upper reaches of the chamber 16 and the bottom of the tube 22 is open so that material being separated may fall or be blown onto a slinger device 32.

Positioned at the center of the top cover 18 is a bearing member 24 which is supported in place by cover supports 26. A vertical shaft 28 is carried in bearing 24 and is arranged 'with a driven pulley 30 attached to the top end and a slinger device 32 attached near the bottom end. The shaft 28 is radially held at the bottom by a bearing member 34, in turn, supported by radial members 36. The pulley 30 andthe shaft 28 are belt driven and rotate the slinger device 32 which is spaced below the bottom end of the tube 22. The incoming material falls onto the slinger disc 32 from the tube 22 and is thrown outwardly by centrifugal force against wall 38 of the inner is attached to the rotating shaft 28 by a sleeve 42 which is flanged at the bottom to provide a large area of contact on the disc 32. The disc 32 is further stiffened by cross members 44 attached to .its underside. Obviously, the sleeve 42 and cross members 44 could be constructed as one casting if desired.

Extending upwardly from the cross members 44 are vertical support posts 46 (which could be'cast with the sleeve 42 and cross members 44) which are attachedat their upper ends to an annular spinner member 48 (Fig. 1). The member 48 carries a plurality of spaced spinner .blades 50 (Fig. 4) that extend outwardly therefrom substitutes a blower.

Rotation of the fan blades 56 creates air flow and suction which draws the-air in chamber 16 upwardly and blows it into the outer chamber 14. The movement of air produced by the fan blades 56 draws the finer and lighter incoming particles upwardly and moves them outwardly into the chamber 14. The fine particles are 'then carried downwardly, partly by air circulation and partly by gravity into an outlet orifice 60. The heavier and coarser particles, which have sufiicient mass to overcome the suction lift generated by the fan blades 56,

are Whirled against the wall 38 of the chamber 16 and move downwardly by gravity through a funnel member 62 and into'an output chute 64 provided therefor. The

spinner blades 50 also assists in keeping the large particles out of the blower. Ports 74 between the chambers 14 and 16 provide a return air path as indicated by the arrows in Fig. 1.

In the past, the space between the relatively movable .feed tube 22 and the blower sleeve 52 has been a natural place for the accumulation of the light weight particularly the finer or dust particles. This is true because of the up draft created therein by the fan blades 56 and by the fact that the negative pressure in the sleeve sucked! in such dust. As these particles circulated and accum mulated in this space, they tended to grind or erode theassociated parts and to create friction therebetweent Even providing a scraping member 68 between tube 22 and sleeve 52 does not adequately solve the problem. The present invention, therefore, consists in keeping this space clear of such harmful particles. I

A device for accomplishing this consists of an air duct 70 connected to communicate the space between the tube 22 and'blower support sleeve 52 to atmosphere. The duct 70 (Figs. 1 and 2) is connected to the stationary feed tube 22 below an annular bafiie 66 connected to the upper end of tube 22, and extends upwardly through the top cover 18. Above the cover 18, the duct 70 makes a 180 bend 72 and then opens to atmosphere. The 180 bend 72 is included to prevent foreign matter such as rain, etc., from inadvertently falling into the air separating device. Obviously, the device would work satisfactorily with something less than the bend 72.

Fig. 5 shows a view of a modified duct 70a. The modified duct 70a is connected to the annular bafiie 66 from above. The bafile 66 in this instance is provided with an opening 66a that communicates the duct 70a with the space between the tube 22 and the sleeve 52 so that the incoming mass of air flows straight down from atmosphere into the space. The modified duct 70:: has the practical advantage of being easier to install on air separators that have not previously been equipped with such a device.

T he operation of the fan blades 56 in sucking air out of the chamber 16 produces a partial vacuum in chamber 16, and causes air flow through the duct 70 or 70a and into the chamber 16. The air flowing through the duct 70 or 70a is in greater volume than can flow out at the bafiile 66 and this excess volume is drawn, by the suction or negative pressure in the chamber 16, downwardly through the space defined between the feed tube 22 and the sleeve 52 sweeping out dust and preventing the particles of material from entering this space. Most of the air flow out of the space in question, as described in this specification, produces an air sealing efiect because it prevents particles from moving into the space and from collecting between the relatively moving tubular member '22 and sleeve 52.. The small amount of the incoming clean air which flows between the bafile 66 and the tube 52 also keeps this region free of binds and harmful deposits.

Experience has shown that the use of the air duct 70 in the manner described substantially eliminates wear, erosive deterioration, and friction caused particularly by finer particles accumulating in the space between tube 22 and sleeve 52. Obviously, the air duct 70 could be constructed in many different shapes and sizes without departing from the spirit of this invention. Many other changes could also be made in the general arrangement and construction of the various elements by persons skilled in the art.

All such changes and modifications of the present invention which do not depart from the spirit thereof are fully anticipated and covered by this specification which is limited only by the following claims.

Wliat'I claim is:

1. In' an air circulating device comprising a housing having an inner chamber and an outer chamber surrounding said inner chamber and communicating therewith, an inlet feed tube into the inner chamber, spaced relatively movable members positioned in said inner chamber, one of said members having a blower portion attached thereto for circulating air between said chambers whereby an area of decreased air pressure is established in said inner chamber, and conduit means communicating the space between the relatively movable members to atmospheric air pressure for creating air flow from atmosphere through said space and into said inner chamber.

' 2. In an air separating device comprising a housing having an inner chamber and a surrounding outer chainber communicating therewith, an inlet passage into the inner chamber, blower means for circulating air between said inner and outer chambers including a rotating sleeve open at both ends and mounted on the housing in spaced relation about said inlet passage, said blower means establishing an area of decreased air pressure in the inner chamber, conduit means communicating the space between the inlet passage and the blower sleeve to the atmosphere for sucking in air from the atmosphere to the inner chamber, and separate outlets communicating with the inner and outer chambers for removal of the solid fractions following separation.

3. In a mechanical air separating device for separating difierent sized particles of a mixture, a housing having separate chambers for collecting the different sizes of particles, an inlet passage for feeding the mixture into one of the housing chambers including means for intercepting and dispersing the incoming mixture therein, means for circulating air between the separate housing chambers to effect separation of the mixture into its different sizes, said air circulating means including a movable sleeve member which surrounds and is spaced from the inlet passage, an air conduit communicating the space formed between the inlet passage and the movable sleeve member to the atmosphere to cause air flow through said space and into said chambers, and separate outlets communicating with the separate chambers through which the different sizes of separated particles leave the device. I

4. An air seal for an air separating device comprising a stationary member, a movable member circumscribing and spaced from the stationary member, a flange on one of said members substantially closing one end of the space defined therebetween, and a duct member connected tothe stationary member and communicating the space defined between the stationary member and the movable member with a source of greater air pressure than the air pressure in said space for producing air flow thereinto.

5. An air seal for an air separating device comprising a stationary member, a movable member circumscribing and spaced from the stationary member, a flange on one of said members substantially closing one end of the space defined therebetween, and a duct member connected to said flange and communicating the space defined between the stationary member and the movable member with a source of greater air pressure than the air pressure in said space for producing air fiow thereinto.

6. An air seal comprising a stationary member, a movable member spaced from said stationary member, means partially closing the space between said members, duct means communicating said space to atmosphere, and blower means associated with the movable member for reducing the pressure in the space whereby air is drawn in from outside through the duct means and through said space.

7. In a device for separating coarse and fine particles from a supply of unseparatcd particles, a feed conduit for the unseparated particles having an outlet, a blower operatively mounted in spaced circumscribing relation to said feed conduit, said blower including a rotating sleeve open at its opposite ends, said feed conduit and sleeve being spaced apart and forming a space therebetween subject to less than atmospheric pressure during blower operation, a passage communicating said space to ambient atmosphere whereby said blower creates positive air flow free of particles through said passage and into said space, and separate outlets for removal of the coarse and fine particles.

References Cited in the file of this patent UNITED STATES PATENTS 

